Support for the acquisition of a state-of-the-art open-access 800 MHz NMR spectrometer for researchers in central New England is requested. The instrument will be located at the University of Connecticut Health Center in Farmington, CT, in the Gregory P. Mullen NMR Structural Biology Facility, which currently houses spectrometers operating at 400, 500, and 600 MHz. The Facility is operated by a full-time manager supported by the University of Connecticut. The 800 will be utilized by a core group of experienced investigators from the Storrs and Farmington UConn campuses, the University of Massachusetts (Amherst), Connecticut College, Dartmouth College, and Wesleyan and Yale Universities, and will be available to others. Participating investigators will obtain access on a priority basis, determined by a multi-institution scheduling committee. The founding group of investigators comprises 17 laboratories, 12 of which use NMR as a primary research tool, and has demonstrated outstanding NMR-based research into protein structure, function, and folding through its record of publication and external funding. The 800 will complement the existing resources available to these researchers and will enable the investigation of larger, more complex systems through its improved resolution and sensitivity. Gains in resolution will result both from the increased dispersion of nuclear resonances and from near-optimal TROSY effects. For partially folded states or complexes exhibiting chemical exchange, the higher field will improve resolution between states that show intermediate exchange at lower field. The 800 will facilitate field-dependent studies of relaxation used to probe molecular dynamics, and will provide preliminary data prior to experiments at higher field conducted at the national NMR resources. Studies to be supported by the 800 include proteins that participate in repair and replication at the sites of DNA damage, proteins that protect from DNA damage, protein folding intermediates, molecular chaperones, proteins that function as tumor suppressors and their mutants, dynein molecular motor proteins, proteins that function in cell division, the 2 adrenergic receptor, cell signaling proteins, enzymes involved in antibiotic resistance, hemopoeitic cytokines and their receptors, and multi- domain neurite outgrowth initiation factors. [unreadable] [unreadable] [unreadable]